eV-Scale Sterile Neutrino Search Using Eight Years of Atmospheric Muon Neutrino Data from the IceCube Neutrino Observatory
Physical Review Letters American Physical Society (APS) 125:14 (2020) 141801
Review of Particle Physics
Oxford University Press (OUP) 2020:8 (2020)
Abstract:
IceCube Search for Neutrinos Coincident with Compact Binary Mergers from LIGO-Virgo's First Gravitational-Wave Transient Catalog
The Astrophysical Journal: an international review of astronomy and astronomical physics American Astronomical Society (2020)
Abstract:
Using the IceCube Neutrino Observatory, we search for high-energy neutrino emission coincident with compact binary mergers observed by the LIGO and Virgo gravitational wave (GW) detectors during their first and second observing runs. We present results from two searches targeting emission coincident with the sky localization of each gravitational wave event within a 1000 second time window centered around the reported merger time. One search uses a model-independent unbinned maximum likelihood analysis, which uses neutrino data from IceCube to search for point-like neutrino sources consistent with the sky localization of GW events. The other uses the Low-Latency Algorithm for Multi-messenger Astrophysics, which incorporates astrophysical priors through a Bayesian framework and includes LIGO-Virgo detector characteristics to determine the association between the GW source and the neutrinos. No significant neutrino coincidence is seen by either search during the first two observing runs of the LIGO-Virgo detectors. We set upper limits on the time-integrated neutrino emission within the 1000 second window for each of the 11 GW events. These limits range from 0.02-0.7 $\mathrm{GeV~cm^{-2}}$. We also set limits on the total isotropic equivalent energy, $E_{\mathrm{iso}}$, emitted in high-energy neutrinos by each GW event. These limits range from 1.7 $\times$ 10$^{51}$ - 1.8 $\times$ 10$^{55}$ erg. We conclude with an outlook for LIGO-Virgo observing run O3, during which both analyses are running in real time.Computational Techniques for the Analysis of Small Signals in High-Statistics Neutrino Oscillation Experiments
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment Elsevier (2020)
Abstract:
The current and upcoming generation of Very Large Volume Neutrino Telescopes - collecting unprecedented quantities of neutrino events - can be used to explore subtle effects in oscillation physics, such as (but not restricted to) the neutrino mass ordering. The sensitivity of an experiment to these effects can be estimated from Monte Carlo simulations. With the very high number of events that will be collected, there is a trade-off between the computational expense of running such simulations and the inherent statistical uncertainty in the determined values. In such a scenario, it becomes impractical to produce and use adequately-sized sets of simulated events to use with traditional methods, such as Monte Carlo weighting. In this work we present a staged approach to the generation of binned event distributions in order to overcome these challenges. By combining multiple integration and smoothing techniques which address limited statistics from simulation it arrives at reliable analysis results using modest computational resources.In-situ calibration of the single-photoelectron charge response of the IceCube photomultiplier tubes
Journal of Instrumentation IOP Publishing (2020)